2. China’s Polar Silk Road

In 2012, President Xi Jinping took office as the head of the world’s second largest economy and drove China’s relations with the west into a different era. Building upon its rapidly growing economic and military power, the Chinese Government has silently abandoned Deng Xiaoping’s guiding principle for foreign policy – ‘keep [a] low profile with focus on domestic affairs’.Footnote ¹⁶ Instead, since 2013, several initiatives that reflect Xi’s view of the world order were raised and implemented. The Belt and the Road Initiative (BRI) is probably a signature one.

The BRI is an ambitious infrastructure investment plan to connect China with countries across Eurasia and the Indian Ocean.Footnote ¹⁷ In order to implement the BRI, the National Development and Reform Commission (NDRC) and the State Oceanic Administration (SOA) published the Vision for Maritime Cooperation under the Belt and Road Initiative in 2017, which for the first time talks about establishing ‘a blue economic corridor leading up to Europe via the Arctic Ocean’ as part of the BRI. It is elaborated in the section ‘ocean-based prosperity’ that:

In 2018, the ‘Polar Silk Road’ was officially mentioned in China’s first ever Arctic Policy White Paper. As elaborated in Part IV, Section 3.1 ‘Utilizing Arctic Resources in a Lawful and Rational Manner’:

It is noted that the ‘Polar Silk Road’ reflects China’s political will to develop and use Arctic shipping routes. So far this is most likely regarding the Northeast Passage,Footnote ²¹ especially shipping routes along the Russian coastline – the NSR.Footnote ²² In practice, the NSR probably has most potential for commercial use in a warming Arctic. There were 62 transits of the NSR in 2020, compared to 37 in 2019.Footnote ²³ Moreover, geopolitically, China and Russia have been moving closer and closer in recent years, which seems to lay a good foundation for economic co-operation along the NSR. For example, only three days after the US-China Dialogue in Alaska, the Russian Minister of Foreign Affairs visited Beijing, which resulted in the China-Russia Foreign Ministerial Joint Declaration on Issues of Global Governance on 23 March 2021 (2021 Sino-Russia Declaration).Footnote ²⁴ The 2021 Sino-Russia Joint Declaration reaffirmed the Chinese view of the world order by placing importance on ‘international law underpinned by the United Nations’. Moreover, China and Russia upgraded the bilateral relations to a higher level called ‘comprehensive strategic partnership’ in 2019.Footnote ²⁵ This partnership specifically includes Arctic co-operation, which focuses on:

Indeed, Chinese companies have been using the Northeast Passage since 2013,Footnote ²⁷ and boasting ambitious plans. For example, a number of China-Russia projects under the umbrella of the PSR were launched in recent years, such as Yamal LNG, Payakha Oilfield, Zarubino Port in the southeast of Vladivostok, and Arkhangelsk Deepwater Port.Footnote ²⁸

Nevertheless, it is widely known that through the Article 234 ‘Ice-covered Area’ of the United Nations Convention on the Law of the Sea (UNCLOS),Footnote ²⁹ Russia has obtained the legal basis for its special coastal state legislative and enforcement jurisdiction over the NSR. The Chinese Government has taken a nuanced position towards the legal status of the NSR so far. As declared in the 2018 Arctic Policy White Paper, China:

Meanwhile, Chinese academia raised blunt concerns about Russian regulation of the NSR as its domestic waters. Some suggests China should recognize the NSR as a strait used for international navigation,Footnote ³¹ which would allow transit passage. Others say the NSR can neither be defined as a strait used for international navigation, nor as internal waters subject to exclusive coastal state jurisdiction.Footnote ³² They recommend the conclusion of an international convention similar to the Svalbard TreatyFootnote ³³ that could balance the interests between coastal and flag states. There are also suggestions that East Asian countries (China, Japan and South Korea) should strengthen their co-operation to influence the development of international law on Arctic shipping.Footnote ³⁴ Given Chinese academia does have strong influence in China’s Arctic policy-making process,Footnote ³⁵ it is imaginable that in the foreseeable future, as a significant user of the NSR, China may want to shape the current regime for its benefit. However, it seems that Chinese academics, so far, have not mastered the fact that the NSR is not a single route, but a set of different sailing lanes where various international law and Russian regulations apply. In the next section, we will elaborate on the detailed regimes of Russian regulation of the NSR, to be compared with Chinese coastal practice on foreign vessels in Section 4.

3. Russian regulation of the Northern Sea Route

The formation of the contemporary legal regime of the NSR can be traced back to the adoption of the 2012 Federal Law,Footnote ³⁶ which concluded a period of heated discussions regarding the need to overhaul the outdated legal regime rooted in the Soviet times.Footnote ³⁷ By amending a few Federal Laws, the 2012 Federal Law provided the basic paradigm for the new legal regime and the backbone for more specific regulations. As a result, the 1999 Merchant Shipping Code gained prominence as the most relevant legal act for the legal regime of navigation on the NSR,Footnote ³⁸ with Article 5.1 providing the definition of the NSR:

Article 5.1 of the 1999 Merchant Shipping Code has served as the legal basis for more specific Rules of Navigation in the Water Area of the Northern Sea Route (2013 Rules).Footnote ⁴⁰ These navigational rules have been further refined. First, primarily in response to the adoption of the Polar Code, the Ministry of Transport of the Russian Federation amended the 2013 Rules in 2017.Footnote ⁴¹ This proved to be a relatively cosmetic adjustment, adding the requirement for ships to which the Polar Code applies to carry a Polar Ship Certificate. Then, as the competence to adopt the rules of navigation on the NSR moved from the Ministry of Transport to the Government of the Russian Federation,Footnote ⁴² the latter adopted a new edition of the 2020 NSR Rules of Navigation.Footnote ⁴³ This most recent development was situated in the context of another major reshuffle of regulatory competence, with the state nuclear corporation and the operator of nuclear icebreakers, Rosatom, being assigned with new regulatory and managerial responsibilities.Footnote ⁴⁴

To better understand the legal status of the NSR, consisting of different maritime zones, one needs to go back to 1985 and the Soviet decree enclosing the key straits of the NSR with straight baselines. ^{Footnote 45} This legal act has left some uncertainty regarding the applicable regime of navigation, if any, through these straits. The legal status of the enclosed waters according to Russian legislation is internal waters. The UNCLOS, in principle, does not grant any navigational right in internal waters, unless they were not considered internal waters before enclosure by straight baselines. ^{Footnote 46} Based on the analysis of state practice and the relevant international law, one can argue that the right of innocent passage has been preserved in all Russian Arctic straits. ^{Footnote 47} Russian international law scholars seldom discuss this issue explicitly, except for presenting it as a quite uncomplicated case of complete sovereignty. ^{Footnote 48} The United States sticks to its traditional position that at least some of the NSR straits are subject to the regime of transit passage. ^{Footnote 49} Noteworthy, in past years, there has been ongoing work dedicated to amending the Russian Arctic baselines. ^{Footnote 50}

However, the issue of key relevance is the application of a single regime of navigation in the entire NSR, including internal waters, territorial sea, and the EEZ.Footnote ⁵¹ The 2020 NSR Rules of Navigation do not distinguish between areas where navigational rights and freedoms apply and areas where they do not apply. This makes it difficult to assert a navigational right in any specific part of the NSR, at least for commercial ships.

One additional complication relates to the question of applicability of the specific regulations to sovereign immune vessels, including warships. The 2020 NSR Rules of Navigation do not explicitly exempt their application to warships, ^{Footnote 52} but good arguments exist that these regulations apply only to commercial vessels. ^{Footnote 53} Conversely, other authors argue that Russia has applied its NSR regime to all ships. ^{Footnote 54} However, the very development by the Russian authorities in March 2019 of draft legislation addressing the specific aspects of the legal regime of NSR navigation for warships ^{Footnote 55} suggests recognition of a gap in Russian legislation. Further, that this draft has not been adopted may indicate a lack of full support within the Russian administration. At the same time, the communication of the clear idea that foreign warships may be subject to specific requirements of prior notification, pilotage, and icebreaker assistance is an indicator of Russia’s attention to the naval activities of other states in the Arctic.

A closer analysis of the evolution of the Russian legal regime in the last few decades reveals that the 2012 reform and the consequential developments amount to liberalization of the regime of navigation. There has been a clear effort to turn the NSR into an attractive route of global significance.Footnote ⁵⁶ The legal developments, such as an overhaul of the requirement to undergo inspection in a Russian port,Footnote ⁵⁷ the possibility to use the NSR without icebreaker assistance and the concomitant requirement to pay fees,Footnote ⁵⁸ streamlining of the permit processing scheme, and general growth in the regime’s transparency, all testify to the attentiveness of the Russian authorities to the needs of users. However, the liberalization tendencies have proven to meet their limits.

A constant feature of the NSR’s legal regime is that foreign vessels need to seek and obtain permission to enter and navigate the NSR. ^{Footnote 59} Although devised in a way that imposes limited burden on the users, and with the processing of the applications being generally transparent, predictable, and evenhanded, the permit scheme assumes Russia’s right to grant or withdraw permission for the exercise of navigational rights and freedoms in the maritime zones of the NSR.Footnote ⁶⁰ There is no sign of any discussion within Russia to overhaul the permission-based order of navigation in the NSR.

Moreover, Russian regulations include an extensive system of ship reporting within and on a ship’s approach to the NSR. Before approaching the NSR’s Western or Eastern boundary,Footnote ⁶¹ a ship master is required to notify the Marine Operation Headquarters (MOHs) about its planned time of arrival to the relevant boundary 48 hours in advance. ^{Footnote 62} The notification must include detailed information regarding, inter alia, the ship, the crew, type and amount of cargo, fuel capacity, destination and the planned time of arrival to the relevant boundary. Further reports are required upon entering and leaving the area of the NSR. ^{Footnote 63} In addition, after crossing the Eastern or the Western boundary, a daily report with information about the ship and the observed navigational conditions is required. ^{Footnote 64} The MOHs transfer the information collected through reporting to the Administration of the NSR (ANSR) within two hours,Footnote ⁶⁵ which then allows the latter to disseminate this information to other users via the website.Footnote ⁶⁶ In this context, it is interesting to observe a resurrection of the MOHs. The body was abolished with the introduction of the 2013 Rules,Footnote ⁶⁷ leaving the ANSR as the principal body for ensuring safety of navigation and environmental protection from vessel-source pollution in the water area of the NSR. The tasks of the ANSR were generally limited to administering the permit scheme and sharing information. ^{Footnote 68} The 2020 Rules of Navigation allocate the task of organizing navigation in the water area of the NSR to Rosatom, through the MOHs.Footnote ⁶⁹ The MOHs are the recipients of the detailed reports (upon entry, leaving, daily reports). ^{Footnote 70} Moreover, the MOHs provide shipmasters with detailed information on the ice situation, recommend routes and warn about especially dangerous ice phenomena, and if necessary, it can give instructions on actions to be taken to ensure the safety of navigation. ^{Footnote 71} The re-introduction of the last element is quite remarkable in the context of real-time decision-making, as the ANSR’s mandate in the time between 2013 and 2020 did not include active interference with ships’ operations. During that time, only the ships that were operating under icebreaker assistance were required to follow icebreaker’s instructions. Those that navigated independently were only required to stick to their navigational plan. The new edition of the navigational rules has tightened, once again, the coastal state control of ships’ operation, regardless of whether navigating independently or with icebreaker assistance.

One of the landmark features of the 2012 reform was the decision to allow ships with sufficient ice strengthening to navigate without icebreaker assistance and without the need to pay the fees. Item 30 of the 2020 NSR Rules stipulates that only icebreakers registered in Russia are entitled to provide icebreaker assistance. This means that a foreign icebreaker can use the NSR but cannot provide icebreaker assistance to other vessels navigating within the NSR. In addition, it may be noteworthy that the 2020 Amendments reinforced the requirement of icebreaker assistance by requiring a copy of the Contract for icebreaker assistance (for ships for which such escort is mandatory according to the criteria for the admission) attached to the application for permission.Footnote ⁷² As a result, while many ships are exempted from icebreaker assistance and fees, those subject to such a requirement will have to rely on a Russian monopolist.

Finally, given the direction of the 2012/2013 liberalization, it was not unreasonable to expect even more transparency of the NSR legal regime in some remaining areas. With respect to the NSR fees, there have been developments aiming to increase transparency in the NSR fee system, especially those fees charged by Atomflot.Footnote ⁷³ However, the transparency of the entire system has been compromised to a large extent by the ability of the providers of icebreaker assistance to apply discounts, as is the case with Atomflot, and the relatively unconstrained discretion to calculate fees by all other organizations. ^{Footnote 74}

With respect to enforcement, there has long been recognition that the capacity to enforce violations needed improvement, and the ANSR closely monitored all shipping movements on the NSR and flagged instances of non-compliance by both Russian and foreign ships. The lack of precise rules and procedures for enforcement still constitutes a legal gap that most likely exists due to the relative infancy of the NSR legal regime, a gap that is expected to be filled at some point.Footnote ⁷⁵ At the same time, an important negative development occurred in the aftermath of the Boris Vilkitsky incident. ^{Footnote 76} Since the incident, the ANSR has stopped publishing any information about violations of the Rules of Navigation. It appears, therefore, that the concern for transparency reached its peak in 2018, as it silently gave way to co-ordination and economic efficiency.Footnote ⁷⁷

The essence of the NSR’s regulatory regime is that Russia welcomes the use of the NSR by foreign ships but does not seem to be ready to compromise on some of the unilaterally established parameters, such as the requirement to obtain permission, the requirements to submit reports and prior notification, and specific rules for icebreaker assistance. Other states may be concerned about the consistency of these requirements with international law, particularly Article 234 of the UNCLOS. It is remarkable that although this provision grants the coastal state additional and imprecisely limited powers, Russia was, for a long time, hesitant to link the specific requirements of its domestic NSR legal regime with this clause, at least explicitly. ^{Footnote 78} Although Article 234 has not been referenced in the relevant legislation, when pressed, the ANSR deemed it necessary to refer to this provision explicitly in the note handed to the Arctic Sunrise by the ANSR. ^{Footnote 79} This open recognition in an official statement constitutes a development towards clarification of Russia’s position on the international legal basis for the regulation of navigation on the NSR.

However, there is also a dose of ambiguity illuminated by the description of the NSR as a ‘historically developed national transport line of communication of the Russian Federation’. ^{Footnote 80} It is unclear whether the aim of this clause is to invoke any additional rights over the NSR, ^{Footnote 81} render the legal status of the NSR ‘still not easy to comprehend’, ^{Footnote 82} or assuage nationalistic sentiments. ^{Footnote 83} In any event, one cannot preclude this being used to support a different narrative in the future, for example if the applicability of Article 234 is called into question because of climate change.

4. China’s coastal practice

China has a mainland coastline of 18,000 km and 6,900 islands. The total sea areas claimed under China’s jurisdiction is about 3,000,000 km², which include Bohai Sea, Yellow Sea, the East China Sea, and South China Sea. There were several authorities that used to be involved in law enforcement in sea areas under China’s jurisdiction. These included the Sea Police of the Border Control Department of the Ministry of Public Security, the Sea Patrol of the Maritime Safety Administration (MSA) of the Ministry of Transport, the State Fisheries Administration of the Ministry of Agriculture, the China Marine Surveillance of the State Oceanic Administration, and the Bureau of Anti-Smuggling at Sea of the China Customs. As part of the effort to become a maritime power, the China Coast Guard was established in 2013,Footnote ⁸⁴ which incorporates most law enforcement authorities, apart from the Sea Patrol. In 2021, China adopted its Coast Guard LawFootnote ⁸⁵ and comprehensively updated its Maritime Traffic Safety LawFootnote ⁸⁶ after nearly four decades. It is therefore a good timing to briefly assess China’s coastal practice in this new era.

China has been consistently embracing the approach of straight baselines. In 1958, amid tension between China and the United States in the Taiwan Strait, the Chinese Government published the Declaration on China’s Territorial Sea, which states that the baseline for measuring the breadth of its territorial sea is ‘the line composed of the straight lines connecting basepoints on the mainland coast and on the outermost of the coastal islands’.Footnote ⁸⁷ This is reflected by the 1992 Law on the Territorial Sea and the Contiguous Zone of the People’s Republic of China.Footnote ⁸⁸ It is provided by Article 3 that ‘The People’s Republic of China (PRC)’s baseline of the territorial sea is designated with the method of straight baselines, formed by joining the various base points with straight lines.’ In 1996, the Chinese Government published a number of geographic co-ordinates to define its straight baselines along large parts of China’s coast and the Xisha/Paracel Islands.Footnote ⁸⁹ The straight baselines around Xisha/Paracel Islands raised some concerns, not only because of sovereignty disputes of the islands between China and Vietnam,Footnote ⁹⁰ but also whether archipelagic straight baselines can be established by continental states.Footnote ⁹¹ Moreover, China declared its straight baselines of Diaoyu/Senkaku Islands on 10 September 2012,Footnote ⁹² which was immediately protested by Japan.Footnote ⁹³

According to the 1992 Law on the Territorial Sea and Contiguous Zone, China has made it clear that foreign warships must seek approval from the Chinese Government before entry into its territorial sea.Footnote ⁹⁴ The 1992 Law on the Territorial Sea and Contiguous Zone also provides that competent authority (in this case, Maritime Safety Administration) is entitled to require foreign vessels to exercise their right of innocent passage through China’s territorial sea to use designated sea lanes or traffic separation schemes.Footnote ⁹⁵ China has established several mandatory shipping routes along its coastal waters.Footnote ⁹⁶ In 2011, the Ministry of Transport published the National Plan for Ship Routeing in Coastal Sea Areas,Footnote ⁹⁷ and stated that a total of 26 shipping routes should be designated. This includes six trunk lines (Laotieshan Shuidao, Cheng Shan Jiao, Estuary of Yangtze River, Taiwan Strait, Estuary of Pearl River, and Qiongzhou Strait), five port areas (Dalian, Qingdao, Rizhao, Ningbo, and Xiamen) and 15 other lines.Footnote ⁹⁸ So far, all these shipping routes are within China’s territorial sea or in its internal waters or port areas, even for the Taiwan Strait between Mainland China and Taiwan.Footnote ⁹⁹

Article 19 of the 2021 Maritime Traffic Safety Law further provides the domestic legal basis for the MSA to establish, adjust and publicize ship routeing and reporting areas, traffic control areas, restricted navigation areas, safety operation areas, and outer anchorage. Moreover, foreign submarine, nuclear-powered vessels as well as ships carrying radioactive and other hazardous wastes are required to report to the MSA when entering and leaving China’s territorial sea.Footnote ¹⁰⁰ Furthermore, compulsory pilotage can be imposed in China’s coastal waters, rivers, and ports,Footnote ¹⁰¹ for:

Nevertheless, given the 2021 Maritime Traffic Safety Law applies to all sea areas under China’s jurisdiction,Footnote ¹⁰³ article 19 raised concerns whether China would unilaterally establish ship routeing and reporting areas for foreign vessels in China’s EEZs.Footnote ¹⁰⁴

The 1998 Law on the Exclusive Economic Zone and the Continental Shelf of the People’s Republic of ChinaFootnote ¹⁰⁵ set up the management regime for several foreign activities in China’s EEZs, including fisheries,Footnote ¹⁰⁶ geological survey,Footnote ¹⁰⁷ marine scientific research,Footnote ¹⁰⁸ and laying underwater pipelines.Footnote ¹⁰⁹ Approval from the Chinese Government is essential for all above-mentioned foreign activities to be carried out in China’s EEZs. The 1998 Law on the Exclusive Economic Zone and the Continental Shelf is silent about ship routeing and reporting. Nevertheless, it provides that ‘competent authorities can take necessary measures to prevent, reduce and control marine pollution to protect the marine environment of China’s EEZ and continental shelf’.Footnote ¹¹⁰ For example, in the Preamble of the Basel Convention on Controlling Transboundary Movements of Hazardous Wastes and their Disposal,Footnote ¹¹¹ it is recognized that a state has the sovereign right to ban the entry or disposal of foreign hazardous wastes and other wastes into its territory. As a contracting party to the Basel Convention, China has banned the transit of hazardous wastes within its internal waters and territorial sea.Footnote ¹¹² Furthermore, the 2010 Regulation on the Prevention and Control of Marine Pollution from VesselsFootnote ¹¹³ extends its application to other sea areas under China’s jurisdiction (e.g., the EEZ).Footnote ¹¹⁴ Whenever vessels carrying hazardous waste want to transit China’s EEZ, an approval from the Ministry of Ecology and Environment is required.Footnote ¹¹⁵ There are also mandatory ship routeing systems and ship reporting systems imposed on these vessels.Footnote ¹¹⁶ This kind of practice is in contrast from many western countries, such as Germany and the United Kingdom, who have declared that the Basel Convention shall not affect navigational rights and freedom as provided by the UNCLOS.Footnote ¹¹⁷

As mentioned above, China Coast Guard is now the most powerful administration to conduct law enforcement at sea areas under China’s jurisdiction.Footnote ¹¹⁸ According to Article 21 of the Coast Guard Law:

It is argued by Sakamoto that Article 21 is potentially in violation of the sovereign immunity as provided by Article 236 of the UNCLOS.Footnote ¹²⁰ Further, the Coast Guard can establish temporary maritime alert zones in sea areas under China’s jurisdiction in case of:

1. 1. carrying out maritime safety and security missions;

2. 2. cracking down crimes at sea;

3. 3. dealing with incidents;

4. 4. protecting and preserving marine resources and marine environment; and

5. 5. other necessary conditions.Footnote ¹²¹

The maritime alert zone would limit or prohibit foreign vessels’ navigational rights in that particular sea area.

5. Concluding remarks

The analysis of coastal state practices of China and Russia reveals quite remarkable commonalities. Both are driven by the concern about the potential adverse effects of uncontrolled foreign shipping in proximity to their coasts. The coastal regulations of both countries show evident traits of efforts to maximize their exclusive authority to prescribe and enforce laws and regulations.

Both have embraced the use of straight baselines attracting international protests. Moreover, both express concern over the operation of foreign warships in their maritime zones, with Chinese legislation being more specific and stringent than Russian NSR regulations. While the NSR regime relies on a system of ship reporting and routeing measures, ensuring in its totality a level of control by the Russian authorities, the recent Chinese legislation seems to follow suit. The reporting requirements for ships exercising navigational rights, the domestic legal basis for additional routing measures, including compulsory pilotage, may raise similar concerns from foreign powers, especially if the specific requirements are adopted unilaterally. The potential for furthering an expansive interpretation of the scope of China’s coastal state jurisdiction over foreign vessels navigating in its EEZs might even be more controversial.

China’s maritime narrative – projecting the interest in tailoring the regulatory regime of the NSR to match its global maritime agenda, may, ironically, suffer from the more inward-looking approach in its coastal waters. China’s ability to successfully develop the PSR would be best served by asserting the full scope of its navigational rights and freedoms. However, China’s rhetoric on this question remains much more careful in tone than the one embraced by the USA. ^{Footnote 122} One reason for this may be that the ‘coastal-oriented’ posture constrains China’s capacity to herald a full-fledged maritime position in the Arctic. China’s strong ‘maritime-oriented’ narrative would be more convincing to the international community if supported by a consistent approach in the areas under its own coastal jurisdiction. ^{Footnote 123} At the same time, it does not come as a surprise that Chinese interests in areas closer to shore take clear precedence over China’s more remote interests in the Arctic.

The question of the (in-)applicability of Article 234 (Ice-covered Area) of the UNCLOS in the era of climate change might be another elephant in the room for both Russia and China. Russia’s cautious endorsement of Article 234 as the international legal basis for its jurisdiction over the NSR may necessitate an argument emphasizing the object and purpose of the Convention, with the effect of leaving the application of Article 234 independent of the future changes in ice coverage. ^{Footnote 124} Although more challenging to defend internationally, an alternative for Russia might be to stress the historical efforts in developing the NSR and its alleged customary international legal status. Given that both arguments may lead to the same result: Russia’s attempt to defend its exclusive control over the NSR, it is not evident that China would take a principled and transparent position on that question either.

To be sure, an outright direct challenge of Russian coastal state regulations, either through clear diplomatic communication or freedom of navigation operation, is a tool, not the goal. It is possible to meet the goals represented by the PSR in the Arctic without upsetting the status quo. The change of the ‘order’ may occur incrementally, for which the fundamental prerequisite is ‘presence’, accompanied by the power sufficient to challenge the pre-existing power structures gradually. The Polar Silk Road, via infrastructural developments and under the condition of the generally amicable relationship with Russia, may provide other tools to construct such presence, without forcing China to embrace the western understanding of navigational rights and freedoms. For now, the careful and vague statements testify to the lack of complete satisfaction with the status quo, but the preferred modality of order change may be more akin to erosion than confrontation.

Besides, considering the shared view of the world order being predominantly based on non-interference in domestic affairs as the pillar of the Westphalian understanding of sovereignty, Russia and China may be expected to tolerate, though not essentially accept, each other’s security concerns. When the latter gives rise to controversial maritime claims pursued by one, the other might hesitate before publicly confronting them.